A mobile communications network is typically made up of a plurality of cells. Each cell includes a radio base station, with each base station connected to a mobile switching center or a packet service node that manages communications sessions between mobile stations and terminals coupled to a public switched telephone network (PSTN) or a packet-based data network. Communications between mobile stations and base stations are performed over wireless links.
Traditional wireless protocols provide for circuit-switched communications. Such protocols include time-division multiple access (TDMA) protocols and code-division multiple access (CDMA) protocols. In a circuit-switched network, a channel portion between two endpoints (e.g., two mobile stations) is occupied for the duration of the connection between the endpoints.
However, with the wide availability of the Internet and intranets, packet-switched communications (e.g., web browsing, electronic mail, and so forth) have become more common. Generally, a circuit-switched connection is an inefficient mechanism for communicating packet data. As a result, third generation (3G) and beyond wireless technologies are being developed and implemented to provide higher bandwidth and more efficient packet-switched communications (of data as well as voice and other forms of real-time data) over wireless networks.
One example of a packet-switched wireless technology is defined by the CDMA 2000 family of standards, developed by the Third Generation Partnership Project 2 (3GPP2). A CDMA 2000 wireless communications network is capable of supporting both circuit-switched services and packet-switched services. For TDMA, packet-switched wireless communications protocols have also been developed, such as the Enhanced General Packet Radio Service (EGPRS) protocol as defined by the 3GPP (Third Generation Partnership Project) UMTS (Universal Mobile Telecommunications System) Release 1999 Standard, and others.
Typically, for a mobile station to transmit packet data over a reverse link from the mobile station to a base station, the base station has to first schedule a traffic channel for the mobile station to send the desired data. For example, in a CDMA 2000 wireless communications network, packet data is carried in a reverse supplemental channel (R-SCH). A base station schedules an R-SCH for a mobile station to transmit packet data over the reverse wireless link. However, the requirement of scheduling is a relatively slow process, since signaling (request and grant signaling) has to be exchanged between the mobile station and the base station to perform the scheduling. The amount of time it takes for the mobile station and base station to exchange request and grant signaling adds to the overall delay in the transmission of packet data. The exchange of request and grant signaling also consumes valuable bandwidth in the air interface between mobile station and base station.